Before I launch into my latest criticism of Donald J. Trump, I want to stipulate something up front.

I recognize that politicians of all stripes play to their “base.” Whether on the left or the right, they know from where they draw their political strength.

There. That said, the president’s belief that the border wall he wants to build between the United States and Mexico is popular with his base and, thus, is worth doing is utter nonsense.

He isn’t just the president of the Republican Party faithful who got him elected — along with a few million formerly loyal Democrats. He represents all 300-plus million Americans. Take it from me, Mr. President, not all of us are the least bit fond of the idea of walling off this country from one of our nation’s most loyal allies.

The wall won’t work. It won’t keep bad guys from coming into the country. It will separate families. It will create untold misery. It also is highly impractical — if not impossible — to build, given all the technical and legal issues involved with property condemnation and how the two countries were to settle the myriad issues relating to its construction.

According to the Washington Post: In a recent interview with the Associated Press, Trump said: “People want the border. My base really wants the border. My base really wants it.”

Really, Mr. President? Do I need to remind this individual that the base comprises a tiny minority of Americans. Indeed, this man finished second in the popular vote count to Hillary Rodham Clinton. Sure, he won where it counted — the Electoral College — but the popular vote disparity wasn’t even close.

He’s not the first pol to proclaim his base’s support for controversial policy initiatives. He won’t be the last.

However, he is the man of the moment. Remember, sir, that you are every American’s president, whether you — or millions of your constituents — care to admit it.